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SCIENCE-GOSSIP. 



CONDUCTED BY F. SHILLINGTON SCALES, F. R.M.S. 



Gregarinidae. — A writer in the "Journal of 

 Applied Microscopy " has a useful and practical note 

 on how to obtain and keep Gregarinidae. He calls 

 attention to the inadequate instructions given in most 

 text-books on matters of this sort, directions such as, 

 "Take a drop of water containing amoebae," &c. , 

 reminding one of the reputed old cookery-book in- 

 struction : "First catch your hare." Gregarinidae 

 may be found, however, according to this writer, 

 "more or less abundantly, usually less so when you 

 come to look for them, in the intestines of insects 

 and of other invertebrates. But in the alimentary 

 canal of the yellow-jointed larvae of Tenebrio molitor 

 they may be found at all times, and in abundance. 

 This is the black beetle found in granaries, mills, 

 barns, &c. Its larvae, commonly known as meal- 

 worms, and often erroneously called wire-worms, 

 may be found in abundance in flouring mills, feed- 

 stores, under boards and bags that have lain for 

 several months, or under feed-boxes in stables— any- 

 where, in fact, where ground grain is stored. The 

 best time is when repairs are being made in a neigh- 

 bouring mill." The larvae may be kept for an in- 

 definite time, without further attention, by simply 

 placing them in glass or stone jars with plenty of the 

 grain debris in which they are found, occasionally 

 adding more meal, dry-rotten wood or rags. At 

 certain times of the year they are apt to metamor- 

 phose rapidly if too well fed, and by keeping the jar 

 covered the beetles depositing eggs produce a new 

 brood, but this is likely to deplete the stock. " To 

 find the Gregarinidae for demonstration or study, 

 snip off with small scissors both ends of a larva, seize 

 the protruding (white) intestine with forceps, draw it 

 out, and tease a portion in normal salt solution (water 

 will do) on a slide. Cover, find with the low-power 

 minute, 6blong, transparent bodies, and study with 

 any higher objective to suit." The writer adds : 

 "The larvae, by the way, serve another purpose; 

 they are used for feeding certain birds or chameleons, 

 &c. , so that in large cities they may be found for sale 

 at bird stores." 



Amos TOPPING. — There is scarcely an amateur 

 microscopist who is not acquainted with the name of 

 Amos Topping, or who does not possess some of the 

 objects prepared by him. The news of his death, 

 which took place on February 25th, was received 

 with deep regret. Although he was sixty-nine years 

 old, he carried his age well, and had the heart and 

 manners of a young man. His genial disposition, 

 sympathetic nature, and even temper gained for him 

 warm friends wherever he went. He may be said to 

 have died in harness. It was his rule to call upon 

 London opticians, with whom he did business, every 

 week ; and so recently as February 22nd, three days 

 before his death, he paid his usual visits and seemed 

 to be in his ordinary state of health. His death was 

 due to syncope, and was quite sudden and unexpected. 



His life had been entirely devoted to microscopical 

 work. Mr. Topping's father enjoyed a high reputa- 

 tion in his day for his preparations for the micro- 

 scope, and the son began to take part in the work at 

 the early age of twelve years. For a period of fifty- 

 seven years he has sent forth to the world objects of 

 exquisite beauty, much above the average in their 

 freedom from imperfection, and all characterised by 

 great care and neat finish. In every department of 

 his work he was extremely successful, but he has 

 always been noted for one particular slide, and that 

 is the proboscis of the blow-fly. No other preparer 

 has succeeded in so mounting this subject as to 

 render it sufficiently flat for use as a test-object ; and 

 unless some other worker knows the secret, it is 

 likely to become one of the lost arts, and, as we at 

 present know it, a rarity. Mr. Topping was always 

 a little reticent regarding his method of preparing 

 this object, and if he were asked whether he would 

 mind saying how it was done, he promptly replied 

 " With pleasure, sir," and proceeded as follows : 

 ' ' I put a piece of sugar upon my bench and hold a 

 blow-fly very closely to it ; directly he puts out his 

 proboscis to touch the sugar, I just snip off the 

 tongue with a pair of scissors I keep handy for the 

 purpose, and straightway mount it." With the death 

 of Mr. Topping one of the links wdth the early days 

 of practical microscopy is broken, and the whole 

 microscopical world is the richer for his years of hard 

 work and the poorer by his death. He leaves a 

 widow, who was helpmeet, not only in his domestic 

 life, but in his business labours, for forty-six years. 

 He leaves also three daughters. — Fred. IV. Watson 

 Baker, 313 High Holborn, London. 



Habit of Amusement in Rotifers. —Under 

 this heading in a recent number of the ' ' New York 

 Journal of Popular Science," a note by Mr. James 

 Weir, jun., M.D. , describes inter alia a rotifer which 

 he has named Melicerta copeii found in Tennessee. 

 This rotifer must be more highly developed intel- 

 lectually than the effete organisms of the Old World, 

 as Dr. Weir has plainly observed it in its " moments 

 of relaxation, during w 7 hich it engages in sports and 

 pastimes." Its residence is a conical tube, which it 

 leaves only " when on pleasure bent." In fact, says 

 Dr. Weir, ' ' I am convinced that it never leaves 

 home unless in search of pleasure. Several of these 

 little animals will meet in a still pool and im- 

 mediately begin a game of 'tag' or 'hide-and-go- 

 seek.'" Then follows a vivid description of the 

 game as played by these exceptionally interesting 

 animals, until one almost wishes one were a boy 

 again, or better still a rotifer. Mr. Weir's observations, 

 however, extend still further, and he has observed in 

 the eyes of Melicerta an arrangement of cells in the 

 retina analogous to the rods and cones of the human 

 retina. Dr. Weir rightly considers this "unique and 

 very wonderful. " He goes on, " When playing ' tag ' 

 this minute animal is directed in the pursuit of its 

 fleeing playmate by sight, and not by another and 

 analogous sense. While at play one of these little 

 creatures will hide behind a small pebble or bit of 

 alga ; when one of its playmates approaches, it will 

 suddenly dart out upon the unsuspecting passer-by 

 and greatly startle it. Their actions are so evidently 

 innocent sport that the most casual and obtuse 

 observer cannot mistake them for anything else." 

 After this remark we accept with gratitude the 

 further statement, " When we take into consideration 

 the fact that this animalcule is almost microscopic in 

 size, and that it is of very low organisation, this 

 habit of amusement seems very wonderful indeed." 



